Approaches - Biological Flashcards
Define genotype
Genetic codes for physical/ behavioural characteristics inherited from parents
Define phenotype
The expression of the genetic characteristic, this can differ from genotype due to environmental effects
What percentage of genes do MZ twins share?
100%
What percentage of genes do DZ twins share?
50%
What is a concordance rate?
it is the likelihood of one twin having the characteristic if the other twin has the characteristic (a measure of correlation).
What is diathesis stress?
Suggesting a disorder is the result of the interaction between a pre-existing vulnerability (ie genetic genotype) and environmental stressors (i.e personal loss, abuse, drug use)
What is evolution
The development of successive generations of natural organisms due to adaptation to the environment
What is the theory of natural selection?
Darwin: Individuals in a species vary due to genetic differences. Variances most suited to the environment give a survival and reproductive advantage These genes are more likely to be passed to the next generation.
What is the endocrine system
A chemical messaging system throughout the body. Releases hormones that enter the blood stream. Slower than the nervous system, but with longer lasting effects
What is the pituitary gland?
Known as the master gland, controls the release of hormones from the other glands
What is the adrenal gland?
Release adrenaline/ noradrenaline as part of the fight or flight response. Adrenaline increases heart rate, constricts blood vessels increasing blood flow and raising blood pressure which diverts blood away from the skin, kidneys and digestive system
What is the reflex arc?
A collection of cells that transmit information from the source, decide responses and make the response happen
What is the function of sensory neurons?
They send information from the sense to the brain
What is the function of relay neurons?
They connect with other neurons, mostly found in the brain/CNS - they analyse sensations, interpreting meaning, deciding on responses. They are found between the sensory and motor neurons.
What is the function of motor neurons?
Send messages along Axons from the brain to the muscles/ effectors
What makes up the reflex arc?
Sensory neuron, relay neuron and motor neuron
Briefly explain synaptic transmission
An action potential/ nerve impulse travels down the presynaptic neuron’s axon. This causes vesicles to release neurotransmitters into the synaptic cleft. Neurotransmitters detected at the post synaptic neuron’s receptor sites influence if the post synaptic neuron fires.
What are neurotransmitters? What are the two types?
Neurotransmitters are chemical messengers that work in the synaptic cleft. Neurotransmitters can be inhibitory (ie Serotonin) making post synaptic neurones less likely to fire (ie Dopamine) making post synaptic neurones more likely to fire an impulse
Explain summation
Summation is the net effect of inhibitory and excitatory influences on the post synaptic neuron results in it being more or less likely to fire.
If the net effect is _________ the neuron will be more likely to fire
excitatory
If the net effect is _________ the neuron will be more likely to fire
inhibitory
What effect to re-uptake inhibitors have?
Drugs often work by influencing the re-uptake system. For example, re-uptake inhibitors like SSRIs keep serotonin in the synaptic cleft
What is the nervous system?
The collection of nerve cells across the body that sends electrical messages
What is the peripheral nervous system?
Information from the senses across the body to the brain, decisions from the brain to the body
